1. Field
The present disclosure relates generally to aircraft and, in particular, to detecting moisture in porous materials in aircraft. Still more particularly, the present disclosure relates to a method, apparatus, and system for detecting moisture in panels in aircraft.
2. Background
Aircraft are being designed and manufactured with greater and greater percentages of composite materials. Composite materials are used in aircraft to decrease the weight of the aircraft. This decreased weight improves performance features such as payload capacities and fuel efficiencies. Further, composite materials provide a longer service life for various components in an aircraft.
For example, composite parts such as composite panels are used in aircraft for walls, closets, galleys, and other structures or monuments in aircraft such as commercial airplanes. These composite panels may be composite sandwich panels that are comprised of a core between two face sheets. The core may be a honeycomb core, a foam core, or some other suitable type of core. Further, in some cases, a decorative laminate may be placed on a face sheet or may be used as the face sheet. In this manner, the composite sandwich panel may have logos, color, or designs for a particular airline.
One problem with these composite sandwich panels and other structures that have porous materials is moisture. Moisture in a composite sandwich panel can cause bubbling. Bubbling is aesthetically undesirable especially when the bubbling occurs in locations visible to passengers, such as in the passenger cabin within a commercial airplane.
This occurrence in a structure in the passenger cabin is a problem that can disrupt the delivery of a commercial airplanes when bubbling is discovered. Further, the discovery of bubbling in composite sandwich panels during production of a commercial airplane may result in delays. Reworking composite sandwich panels with bubbling increases the time and expense for producing an airplane. Disruption in the production line may occur.
Further, moisture within a composite sandwich panel may not immediately manifest itself in the form of bubbling. When bubbling is discovered, rework may be performed.
Therefore, it would be desirable to have a method and apparatus that take into account at least some of the issues discussed above, as well as other possible issues. For example, it would be desirable to have a method and apparatus that overcome a limitation with detecting moisture in porous structures such as composite sandwich panels.